Coating compositions based on aqueous polyurethane dispersions have been known for some time. In general, the polyurethanes on which the polyurethane dispersions are based are produced by polyaddition of polyols with diisocyanates, the co-condensation of components capable of salt formation having an advantageous effect on dispersibility. Polyurethane urea dispersions, which are also used as coating compositions, are formed in the presence of chain-extending agents, such as diamines.